org.glassfish.hk2.api.messaging.Topic Maven / Gradle / Ivy
/*
* Copyright (c) 2014, 2018 Oracle and/or its affiliates. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v. 2.0, which is available at
* http://www.eclipse.org/legal/epl-2.0.
*
* This Source Code may also be made available under the following Secondary
* Licenses when the conditions for such availability set forth in the
* Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
* version 2 with the GNU Classpath Exception, which is available at
* https://www.gnu.org/software/classpath/license.html.
*
* SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
*/
package org.glassfish.hk2.api.messaging;
import java.lang.annotation.Annotation;
import java.lang.reflect.Type;
import java.util.Set;
/**
* This service is used for publishing events to subscribers. The type of the Topic is
* the type of event that will be distributed
*
* @author jwells
* @param The type of event to be distributed to subscribers
*
*/
public interface Topic {
/**
* Publishes a message to all subscribers
*
* @param message The non-null message to send to all current subscribers
* @throws IllegalStateException If there is no implementation of
* {@link TopicDistributionService} to do the distribution of the message
*/
public void publish(T message);
/**
* Returns an Topic that is further qualified
* with the given name
*
* @param name The value field of the Named annotation parameter. Must
* not be null
* @return A topic further qualified with the given name
*/
public Topic named(String name);
/**
* Returns an Topic that is of the given type. This type
* must be more specific than the type of this Topic
*
* @param type The type to restrict the returned Topic to
* @return A Topic restricted to only producing messages of the given type
*/
public Topic ofType(Type type);
/**
* A set of qualifiers to further restrict this Topic to.
*
* @param qualifiers The qualifiers to further restrict this Topic to
* @return An Topic restricted with the given qualifiers
*/
public Topic qualifiedWith(Annotation... qualifiers);
/**
* Gets the type of the topic, in order to match the message
* to subscribers
*
* @return the Type of this topic. Will not return null
*/
public Type getTopicType();
/**
* The qualifiers associated with this Topic. Messages
* should only be distributed to subscribers that have
* matching qualifiers
*
* @return the non-null but possibly empty set of
* qualifiers associated with this Topic
*/
public Set getTopicQualifiers();
}